Test your memory

This is wild, try it.

Here is a math trick so unbelievable that it will stump you.
Personally I would like to know who came up with
this and why that person is not running the country.
1. Grab a calculator. (You wont be able to do this in your head)
2. Key in the first three digits of your phone number (NOT the area code)
3. Mutiply by 80
4. Add 1
5. Mutiply by 250
6. Add the last four numbers of your phone number
7. Add the last four numbers of your phone number again
8. Subtract 250
9. Divide number by 2

Do you recognize the answer?